<meta charset="UTF-8">
<style>
    body{
        background: aliceblue;
    }
    div{
        font-size: 50px;
        position: absolute;
        left: 100px;
        top: 50px;
    }
</style>
<div>🐝</div>
<script>
    document.onmousemove = function(evt){
        var e = evt || window.event
        var left = e.pageX
        var top = e.pageY
        var divObj = document.querySelector('div')
        divObj.style.left = left + 'px'
        divObj.style.top = top + 'px'
    }
</script>